Citrus processing system and method

Abstract

A system for processing citrus fruit includes a juice extractor and finisher from which wet peel and pulp and finished juice are obtained. The stream of wet peel pulp is separated into press liquor and press cake components. The press cake is introduced into a dryer where it is contacted by superheated steam so that the press cake is elevated to a high temperature without oxidation, and moisture is driven from the press cake to provide surplus steam and dried pulp from the dryer. The press liquor is conducted to an evaporator where moisture is removed providing a molasses concentrate. The finished juice is conducted to another evaporator where moisture is removed providing a juice concentrate. The surplus steam is directed from the dryer to both of the evaporators to provide the heat for evaporation. The remainder of the steam from the dryer is directed to a heat exchanger where it is superheated without dilution with noncondensible gases for a subsequent passage through the dryer. Thus, it is unnecessary to operate a boiler to provide the steam used by the system. Provision is also made for use in the system of the heat contained in the combustion gases which are exhausted from the heat exchanger. This judicious use of heat energy provides a relatively efficient system which conserves energy.

What is claimed is: 
     
       1. A citrus fruit processing system comprising a juice extractor adapted to receive the citrus fruit and having a juice output and a wet peel and pulp output, a means for removing liquor from the wet pulp and peel output coupled to said juice extractor and adapted to receive the wet pulp and peel therefrom, said means for removing liquor having a liquor output and a press cake output,   a dryer coupled to said press cake output and having a dried solids output and a steam output,   a heat exchanger coupled to said steam output and having a superheated steam output, said heat exchanger having an isolated combustion chamber which operates to transfer heat to steam passing therethrough without contact between said steam and combustion products produced in said chamber,   said superheated steam output being coupled to said dryer whereby wet peel and pulp introduced into said dryer is heated by superheated steam until a major portion of the moisture therein is vaporized and emitted through said steam output,   a juice evaporator coupled to said juice output and to said steam output of said dryer, and having a concentrated juice output, said juice evaporator operating to dehydrate the juice,   means for preheating liquor coupled to said means for removing liquor, said means for preheating being connected to receive the exhaust combustion products from said heat exchanger combustion chamber whereby the liquor is preheated by the combustion products, and,   a second evaporator coupled to said means for preheating liquor and to said steam output of the dryer, said second evaporator operating to dehydrate the liquor.   
     
     
       2. A citrus fruit processing system as in claim 1 together with means coupled to said press liquor preheater for recycling a portion of the preheated press liquor to said press, whereby peel and pulp introduced into said dryer is preheated. 
     
     
       3. A citrus fruit processing system as in claim 1 wherein steam passing through said steam output of the dryer is at a temperature of approximately 300° F. and superheated steam passing into said dryer from said superheated steam output of the heat exchanger is at a temperature of approximately 600° F. 
     
     
       4. A citrus fruit processing system as in claim 1 wherein said evaporator includes means for condensing all of the steam therein. 
     
     
       5. A citrus fruit processing system as in claim 1 wherein both said juice evaporator and said second evaporator include means for condensing all of the steam therein.